Ballast water drained from cargo ships such as container ships contains aquatic organisms and bacteria which inhabit in ports where the ballast water is drawn and are conveyed to other countries as the ships move.
As seriously considered the above background, a diplomatic conference at the International Maritime Organization (IMO) adopted the International Convention for the Control and Management of Ships' Ballast Water and Sediments to make the obligation of implementing ballast water control be applied to ships to be built from 2009 onward.
Consequently, it is required to make it possible to drain such clean ballast water as meets the International Convention for the Control and Management of Ships' Ballast Water and Sediments.
Accordingly, it is now a matter of great urgency to develop a sterilization and/or elimination technology in the ballast water which can solve the above problem.
Conventionally, a technology for sterilization by means of injecting ozone into ballast water in parallel with injecting steam and further generating micro bubbles of ozone to promote formation of hydoxyradicals to reduce consumption of ozone has been offered, as seen in Unexamined Patent Application Publication No. 2004-160437(JP).